Neonatal and Postneonatal Pulmonary Hypertension

Area of Science:

• Neonatal physiology
• Pediatric cardiology
• Respiratory medicine

Background:

• Pulmonary vascular resistance (PVR) normally decreases at birth, increasing pulmonary blood flow (Qp). Failure of this transition causes pulmonary hypertension (PH) in infants.
• PH in neonates presents in various forms, including primary, secondary to lung disease, acute in preterm infants with respiratory distress syndrome (RDS), chronic with bronchopulmonary dysplasia (BPD), and post-neonatal.
• Hemodynamically significant patent ductus arteriosus (PDA) can worsen PH in preterm infants, and pulmonary vein stenosis (PVS) may complicate BPD with PH.

Discussion:

• Diagnosis relies on clinical signs, echocardiography, and sometimes cardiac catheterization for intractable cases.
• Treatment strategies involve oxygen, ventilation (invasive/non-invasive), acidosis correction, surfactant, and pulmonary vasodilators like inhaled nitric oxide and sildenafil.
• Early closure of PDA may limit pulmonary vascular remodeling in BPD and PH. Thiamine's role in thiamine-responsive acute PH is also under investigation.

Key Insights:

• Pulmonary hypertension (PH) in infants is a critical condition arising from failed circulatory transition at birth.
• Diverse etiologies and presentations of PH in neonates necessitate tailored diagnostic and therapeutic approaches.
• Interventions like PDA closure and specific vasodilators are key to managing PH and preventing long-term complications.

Outlook:

• Further research into thiamine's role in infant PH could reveal novel therapeutic targets.
• Optimizing ventilation strategies and vasodilator use is essential for improving outcomes in preterm infants with PH.
• Preventing right ventricular dysfunction and failure through early and effective PH management remains a primary clinical goal.